New guidelines from Microsoft will help developers of applications, Web sites, and services avoid the legal problems, negative publicity, and loss of customer trust that come from failing to protect users' privacy. Originally developed by Microsoft for use by its own development teams, the guidelines define key privacy concepts and describe how to enforce privacy constraints in basic application scenarios (such as transferring personal information between the user and the application).

The guidelines are divided into two sections: a set of basic concepts and definitions regarding privacy and a set of best practices for developers.

The document defines important privacy concepts such as "personally identifiable information," "prominent notice," and "explicit opt-in consent." In many cases, the definitions are not Microsoft's but come from various industry groups. For example, Microsoft uses TRUSTe's definition of personally identifiable information. (TRUSTe is an independent organization that monitors and certifies the privacy and e-mail policies of Web sites.)

The recommendations themselves are divided into nine scenarios:

• Transferring personally identifiable information (PII) to and from the customer's system
• Storing PII on the customer's system
• Transferring anonymous data from the customer's system
• Installing software on a customer's system
• Deploying a Web site
• Storing and processing user data outside the customer's premises.
• Transferring user data to third parties
• Interacting with children
• Server deployment

In each scenario, Microsoft provides a list of recommended practices. For example, when transferring PII to and from a customer's system, such as when sending product registration or displaying a user's profile information, the guidelines specify that the vendor should observe the following guidelines (among others):

• Provide prominent notice and get explicit opt-in consent prior to transfer of PII from customer's system
• Provide prominent notice and get explicit consent if the PII being transferred will be used for secondary purposes, such as marketing
• Clearly distinguish between optional and required data
• Transfer sensitive PII to or from a customer's system over the Internet using a secure method that helps prevent unauthorized access.

Although in some cases the guidelines include technical information (for example, the instruction to use secure methods of transferring information recommends 128-bit Secure Sockets Layer encryption), they are intended to be useful regardless of the technology being used to develop the application and therefore aren't specific to the Windows APIs or .NET Framework.

The privacy guidelines can be downloaded from www.microsoft.com/downloads/details.aspx?FamilyID=c48cf80f-6e87-48f5-83ec-a18d1ad2fc1f.